In recent years, an electronic camera is spread more and more, and thus demand for a semiconductor device, for example, a solid-state imaging device (image sensor), including a light-receiving element which is a center part of the electronic camera is continually increased. A technological development for realizing high image quality and high functionality in terms of performance is continued. On the other hand, not only a video camera or a portable camera, but also a mobile phone, a personal digital assistant (PDA), a laptop computer or the like is spread. With the spread, it becomes necessary to make the solid-state imaging device and parts thereof smaller, lighter, thinner for easy portability, and to make the cost of the solid-state imaging device and parts lower for widespread use.
In general, a solid-state imaging device, for example, an MOS type solid-state imaging device has a chip in which a photoelectric conversion unit or an amplifier circuit, and a multilayer wiring layer are formed on a silicon substrate and an on-chip microlens or a color filter is formed on the multilayer wiring layer. Furthermore, the solid-state imaging device is configured to have a terminal in the chip. Then, a chip mounted with a signal processing circuit for processing an output image is connected to the solid-state imaging device.
A chip mounted with a signal processing circuit for processing an output image is connected to the solid-state imaging device. As the solid-state imaging device is multi-functionalized, processing performed by the signal processing circuit also tends to be increased.
In order to obtain a plurality of these functions and make a plurality of chips smaller, various techniques are undertaken. For example, by inputting the plurality of chips in one package using a Silicon in Package (SIP) technology, miniaturization is performed. In this case, there is an advantage that the miniaturization can be realized by combining existing chips; however, since a transmission distance for connecting between chips is long and a fast connection is difficult, there is a problem that it is difficult to realize a fast operation.
On the other hand, there is an effort to make a fast transmission possible by joining a plurality of chips to each other to be bonded (refer to PTL 1).